1SWASP J093010.78+533859.5

1SWASP J093010.78+533859.5
Observation data
Epoch J2000      Equinox J2000
Constellation Ursa Major[1]
A
Right ascension 09h 30m 10.7410s[2]
Declination +53° 38′ 59.825″[2]
Apparent magnitude (V) 9.84[3]
B
Right ascension 09h 30m 10.9127s[4]
Declination +53° 38′ 58.356″[4]
Apparent magnitude (V) 10.98[3]
Characteristics
A
Spectral type K1V + K5V[5]
Variable type Algol[6]
B
Spectral type K3V + K3V[5]
Variable type W UMa[6]
Astrometry
A
Radial velocity (Rv)12.24±0.17[7] km/s
Proper motion (μ) RA: +0.532[2] mas/yr
Dec.: −6.970[2] mas/yr
Parallax (π)23.5622±1.3138 mas[2]
Distance138 ± 8 ly
(42 ± 2 pc)
B
Proper motion (μ) RA: −0.737[4] mas/yr
Dec.: −12.997[4] mas/yr
Parallax (π)14.2625±0.0165 mas[4]
Distance228.7 ± 0.3 ly
(70.11 ± 0.08 pc)
Orbit[7]
PrimaryAa
CompanionAb
Period (P)31.333 hours
Semi-major axis (a)5.762±0.010 R
Eccentricity (e)0
Inclination (i)88.2±0.3°
Orbit[7]
PrimaryBa
CompanionBb
Period (P)5.465 hours
Semi-major axis (a)1.665±0.012 R
Eccentricity (e)0
Inclination (i)86±4°
Details[7]
J093010Aa
Mass0.837±0.008 M
Radius0.832±0.018 R
Surface gravity (log g)4.52 cgs
Temperature5,185+25
−20
 K
J093010Ab
Mass0.674±0.007 M
Radius0.669±0.018 R
Surface gravity (log g)4.62 cgs
Temperature4,325+20
−15
 K
J093010Ba
Mass0.86±0.02 M
Radius0.79±0.04 R
Luminosity6.20±0.05 L
Surface gravity (log g)4.58 cgs
Temperature4,700±50 K
J093010Bb
Mass0.341±0.011 M
Radius0.52±0.05 R
Luminosity7.12±0.05 L
Surface gravity (log g)4.53 cgs
Temperature4,700±50 K
Other designations
RX J0930.1+5339, WDS J09302+5339[8][a]
A: V441 UMa, TYC 3807-759-1[9]
B: V442 UMa, TYC 3807-759-2[10]
Database references
SIMBADdata
A
B

1SWASP J093010.78+533859.5 (abbreviated as J093010), also known as V441 Ursae Majoris and V442 Ursae Majoris is a quintuple star system located in the constellation Ursa Major.[5][7] The star system is located approximately 250 light-years from Earth,[7] and was discovered using data from the "Super Wide Angle Search for Planets" (SuperWASP) project in the Canary Islands.

Description

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1SWASP J093010.78+533859.5 consists of two pairs of stars, designated J093010A and J093010B respectively, as well as a fifth star. The first pair of stars, J093010A, is a detached eclipsing binary (an Algol variable). The two stars within J093010A orbit with a period of about 1.3 days and are separated by about 5.8 solar radii.[7] The second pair of stars, J093010B is a W Ursae Majoris variable; in this pair the two stars are so close as to be touching each other. The two stars within J093010B take about 5.5 hours (0.2277 days) to orbit each other.[6]

The two pairs J093010A and J093010B are separated by about 1.89 arcseconds, so the separation between the two pairs is likely about 130 astronomical units. The fifth star was detected based on stationary spectral lines coming from the direction of 1SWASP J093010.78+533859.5. The fifth star likely orbits J093010A at a further distance than the eclipsing binary.[5]

Variability

[edit]

J093010A is a detached (Algol-type) eclipsing binary. Its magnitude drops from a maximum of 9.44 to a primary minimum of 9.75 and a secondary minimum of 9.58 every 1.31 days. It has been given the variable star designation V441 Ursae Majoris.[11]

J093010B is a contact (W UMa-type) eclipsing binary. Its magnitude drops by 0.28 magnitudes at the primary eclipse and 0.25 magnitudes during the secondary eclipse from a maximum magnitude of 10.55. The period is 0.23 days. It has been given the variable star designation V442 Ursae Majoris.[11]

See also

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Notes

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  1. ^ Simbad assigns the 1SWASP J093010.78+533859.5 designation to component B, but various sources make clear it applies to the whole "system" of four or five stars.[7][5] Similarly, the designation 1SWASP J093012.84+533859.6 is also given to component B, but actually applies to an 18th-magnitude star 18" away.[7]

References

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  1. ^ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
  2. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  3. ^ a b Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (2002). "The Tycho double star catalogue". Astronomy and Astrophysics. 384: 180. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822.
  4. ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  5. ^ a b c d e Koo, Jae-Rim; Lee, Jae Woo; Lee, Byeong-Cheol; Kim, Seung-Lee; Lee, Chung-Uk; Hong, Kyeongsoo; Lee, Dong-Joo; Rey, Soo-Chang (2014). "1SWASP J093010.78+533859.5: A Possible Hierarchical Quintuple System". The Astronomical Journal. 147 (5): 104. arXiv:1402.4575. Bibcode:2014AJ....147..104K. doi:10.1088/0004-6256/147/5/104.
  6. ^ a b c Gazeas, K. (July 2015). "Disentangling the Quadruple System 1SWASP J093010.78+533859.5". Living Together: Planets. 496: 112. Bibcode:2015ASPC..496..112G.
  7. ^ a b c d e f g h i j k Lohr, M. E.; Norton, A. J.; Gillen, E.; Busuttil, R. (June 12, 2015). "The doubly eclipsing quintuple low-mass star system 1SWASP J093010.78+533859.5". Astronomy & Astrophysics. 578: A103. arXiv:1504.07065. Bibcode:2015A&A...578A.103L. doi:10.1051/0004-6361/201525973.
  8. ^ "TIC+318210930". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2025-07-07.
  9. ^ "V441+UMa". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2025-07-07.
  10. ^ "V442+UMa". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2025-07-07.
  11. ^ a b Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085.